1. Field of the Invention
The present invention generally relates to presentation of data on a display device and, more particularly, to managing presentation of query results on a display device.
2. Description of the Related Art
Databases are computerized information storage and retrieval systems. A relational database management system is a computer database management system (DBMS) that uses relational techniques for storing and retrieving data. The most prevalent type of database is the relational database, a tabular database in which data is defined so that it can be reorganized and accessed in a number of different ways. A distributed database is one that can be dispersed or replicated among different points in a network. An object-oriented programming database is one that is congruent with the data defined in object classes and subclasses.
Regardless of the particular architecture, a DBMS can be structured to support a variety of different types of operations for a requesting entity (e.g., an application, the operating system or an end user). Such operations can be configured to retrieve, add, modify and delete information being stored and managed by the DBMS. Standard database access methods support these operations using high-level query languages, such as the Structured Query Language (SQL). The term “query” denominates a set of commands that cause execution of operations for processing data from a stored database. For instance, SQL supports four types of query operations, i.e., SELECT, INSERT, UPDATE and DELETE. A SELECT operation retrieves data from a database, an INSERT operation adds new data to a database, an UPDATE operation modifies data in a database and a DELETE operation removes data from a database.
Processing queries and query results can consume significant system resources, particularly processor resources. Furthermore, one difficulty when dealing with large query results, i.e., query results including a large amount of data, is to accurately render the data of the query results on a display device for presentation to a user. For instance, assume a query result in tabular form having 175 columns and 1500 rows. Accordingly, the query result consists of more than 250,000 data fields which must be displayed to the user on a display device. However, this number of data fields significantly exceeds the number of displayable data fields on the display device.
A number of techniques have been employed to deal with this difficulty. For instance, the complete query result can be displayed in a graphical window having horizontal and vertical scrollbars which allow the user to navigate through the query result. However, navigating through the complete query result to locate selected information therein can be a tedious process for the user. Alternatively, the query result can be split into distinct result units which are separately displayed on the display device. To this end, suitable criteria are required for accurately splitting the complete query result into the distinct result units. Furthermore, suitable presentation rules defining, for instance, a sequence of display of the distinct result units on the display device are required in order to intelligently support the user in navigating through the distinct result units. However, such techniques still require a significant amount of user interaction and are, therefore generally an ineffective means for presenting large query results. In other words, relevant data still needs to be identified manually by the user.
Therefore, there is a need for an effective technique for managing presentation of query results on a display device.